Solar panels and battery to get unlimited range ...

[HaulingAss]

Everyone seems to be missing some basics here.

Teslas charge off of AC voltage (except for the humongous DC Fast Charging).
The slowest acceptable charge is 120V @ 12A AFAIK, without manually dropping the charge current.

The charge current really won't automatically adjust itself (yes, there are exceptions) and that ends up meaning that the solar charging solution will need to pick effectively one and only one charging rate. For the sake of argument, let's say that's 120V @12A, 1440 watts.

Solar production caries throughout the day. As the sun comes up, the voltage on the array slowly increases, as clouds pass over, the voltage decreases. To charge the car, you will need enough voltage to power the inverter to get to AC. If the voltage drops below this, the vehicle will stop charging. If the voltage goes above this amount, power will be lost.

So even if the panels were enough to do something useful to charge the car, you probably have to derate them by 50%, for either not enough sun, or too much sun and energy loss.

If Tesla's allowed DC charging, it could be a different story, it still wouldn't make sense though.

That's what the solar "generator" battery is for. I only use the term "solar generator" because it's so common in the industry to call battery storage systems "battery generators" or "solar generators" even though I don't think it's very accurate or descriptive. I trust you know the basics.

Essentially, you feed the solar energy into the battery generator. Since battery generators can charge while you are drawing 120V current from the inverter you simply charge the car while the sun is shining. This is mostly to prevent the steady and predictable vampire drain that will eventually leave your battery flat (but with good solar conditions, and a good setup, you will be able to steadily add a bit a range to the battery every day). You can also run things off it, lights, charge devices, even a cooler if you have a reasonable solar array. That's in addition to adding a bit of range each day.

I would love it if Tesla offered DC charging inputs! And I'm sure they will some day, but probably not for a couple of years or more. By my estimation, DC solar inputs and a built-in MPPT charge controller would increase the output of your solar array by around 20-25% by bypassing the battery generator.

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[Darthamerica]

Incorrect, you can buy portable solar generator systems now, off the shelf, that do what I described. Plug and play. They have been available for years, but they keep getting more capable and less expensive. It's more a question of whether someone would want to spend the thousands of dollars they cost, give up some of the space in the bed, and it's one more thing to set up and take down when moving camp.

For boon dockers in sunny climates, who don't mind spending that kind of money, it's a viable option.

You said “incorrect” and then reworded what I said. In summary, again, it’s a niche low volume, high cost, DIY project with questionable utility.

 

[tmeyer3]

I can confirm that this works with 800-1200W of panels and a solar generator (combo box of battery, inverter, charge controller etc etc). I have done this multiple times successfully during week-long camps at the beach while using an electric kettle, induction stove, lights, a box fan, and even a microwave one time all from the same generator.

You just plug the vehicle in to a free 120 outlet, then adjust the current from the vehicle as needed. I typically put whatever we generate up to about 50% of the generator's battery into the car during daylight, then stop charging for the night. Resume the next day and away you go. By the end of the week I'm typically nearly full up in my model 3, depending on my soc when I arrived and if I put out the max 1200W or just 800W. Looking forward to doing the same in the CT next month at jalama beach!

I started doing just 800w because all I wanted was MORE soc than I arrived with. And it's more than enough over 5+days to not need to worry about sentry or vamp drain.

 

[HaulingAss]

You said “incorrect” and then reworded what I said. In summary, again, it’s a niche low volume, high cost, DIY project with questionable utility.

I said it was incorrect that it's a DIY project. It's an off-the-shelf, plug and play solution. Yes, it is a high-cost option for a specific use case, no, it's not a DIY project.

 

[Darthamerica]

I said it was incorrect that it's a DIY project. It's an off-the-shelf, plug and play solution. Yes, it is a high-cost option for a specific use case, no, it's not a DIY project.

Please show me this off the shelf solution.

 

[firsttruck]

You said “incorrect” and then reworded what I said. In summary, again, it’s a niche low volume, high cost, DIY project with questionable utility.

As HaulingAss said previously there are several models that have been available for years.

It maybe niche but there seems to be enough volume that there are several competitors with retail ready-made off-the-shelf solar generators that can take solar input and output 230V/240V.

and prices seem to drop every years just like most LFP battery products.

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Charging a Tesla with the EcoFlow DELTA Pro! 15 and 30 amps
Jul 27, 2021
Steve Vandeman


----------------------------------

Three Ways to Charge Your Tesla with Ecoflow Delta Pro ( 1 )!
Apr 24, 2024
WIlliam Sung


----------------------------------

$3,700 Ecoflow Delta Pro 3 ( single unit can out 230V/240v to EV or mini-split )
https://www.ecoflow.com/us/delta-pro-3-portable-power-station#dp3-teaser-E

----------------------------------


$2,800 Anker Solix F3800
https://www.anker.com/products/a1790?variant=43011257827478


Anker's LARGEST Power Station Yet! The Solix F3800 Will Blow Your Mind & Charge Your EV
** even fits in narrow storage area of back of 6-seater Tesla Model X with room for some luggage too.
Oct 18, 2023
Kim Java


----------------------------------

Finally, a power station that runs WELL! This is a game-changer. Anker SOLIX F3800
Nov 9, 2023
Benjamin Sahlstrom


----------------------------------


$4,995 Hysolis Apollo 5K • Ultra-Fast Portable Solar Power Station
The fastest solar generator, fully solar charged in 90 minutes at 4.4kW. With its groundbreaking 5,376 LiFePO4 battery, it can run a full-sized fridge for 60 hrs. It’s built to last and impress.
Battery lasts over +20 years of regular use.
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Modular & expandable with up to 118.3 kwh of LIFEPO4 expansion battery storage
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----------------------------------

 

[HaulingAss]

Please show me this off the shelf solution.

I'm not going to do your shopping for you! Just Google solar battery generator. Look for one that is bundled with solar panels. Stick with the best names. You can generally add panels up to the maximum charge current the unit can handle. That's the most important number in this application, not the number of kWh of battery storage. It should also be able to output 15-20 amps at 120V.

You want the solar input to be at least 1000W, the higher this number, the more solar panels it can run. The battery itself can be as small as possible, as long as the input is high enough. I think you might find what you need with a battery of about 1.5 - 2 kWh.

You just plug your Mobile connector into this and start charging, whenever the sun is shining on the panels.

 

[HaulingAss]

As HaulingAss said previously there are several models that have been available for years.

It maybe niche but there seems to be enough volume that there are several competitors with retail ready-made off-the-shelf solar generators that can take solar input and output 230V/240V.

and prices seem to drop every years just like most LFP battery products.

----------------------------------

Charging a Tesla with the EcoFlow DELTA Pro! 15 and 30 amps
Jul 27, 2021
Steve Vandeman


----------------------------------

Three Ways to Charge Your Tesla with Ecoflow Delta Pro ( 1 )!
Apr 24, 2024
WIlliam Sung


----------------------------------

$3,700 Ecoflow Delta Pro 3 ( single unit can out 230V/240v to EV or mini-split )
https://www.ecoflow.com/us/delta-pro-3-portable-power-station#dp3-teaser-E

----------------------------------


$2,800 Anker Solix F3800
https://www.anker.com/products/a1790?variant=43011257827478


Anker's LARGEST Power Station Yet! The Solix F3800 Will Blow Your Mind & Charge Your EV
** even fits in narrow storage area of back of 6-seater Tesla Model X with room for some luggage too.
Oct 18, 2023
Kim Java


----------------------------------

Finally, a power station that runs WELL! This is a game-changer. Anker SOLIX F3800
Nov 9, 2023
Benjamin Sahlstrom


----------------------------------

That's great, I see now there are 240V models on the market.

Remember, you don't need one with the biggest battery because your truck is the battery. The solar generator is just the pass-through (and the buffer) for the solar electricity. The battery needs to be big enough to put out the kind of charge current you are looking for but you don't need a lot of storage.

 

[Pops]

This is a fun game, I will play. I am aiming for a self contained, no "deployment" solution. It would just pivot up like a tonneau cover to use the bed.

• Canadian Solar TOPBiHiKu7 700w
• EG4 6000XP | 8000W PV Input | 6000W Output | 120/240V Split
• EG4-WallMount Indoor Battery | 48V 280Ah | 14.3kWh
• ~$5,000

The solar panel is about 94"x51". The battery could hold about ~30 miles of charge. With 700w it gathers around 3.5kw per day, or ~5 to 7 miles in ideal conditions.

 

[Crissa]

Your numbers seem a bit optimistic to me.

This is in the post you're quoting:

Of course, panels aren't perfect, nor is the angle, and you're left with not a full footprint.

Maybe, I don't know, read the entire post before calling it 'optimistic'. I was pointing out why off the shelf wouldn't work - but why there's a chance for it to do more.

Elon's flat wrong on this. Vampire drain of electronics and battery management could be completely dealt with via solar panels.

Even on an older ICE car, it can help; as a higher voltage in the battery system lowers the drag of the alternator. On modern ICE cars, which can have clutches to the alternator, and this higher base voltage would encourage the car from employing the alternator altogether. (On my '02 Sentra I used a 12W panel and raise my mpg by 1mpg. Of course, I drove with headlights on 100% of the time using that car, which was known to reduce mpg by 1mpg.)

I have alot of practice with small-scale solar, in this century I have had multiple camping sets that I have integrated into my vehicles.

I don't see a battery here. Without a battery, you will only be able to charge for a very few hours a day. And that's only when it can put out 120V @12A.

Tesla used to let you dial your mobile charger draw below 12amps. Is that no longer true?

The solar panel is about 94"x51". The battery could hold about ~30 miles of charge. With 700w it gathers around 3.5kw per day, or ~5 to 7 miles in ideal conditions.

Tesla monitors the power consumption of the low-voltage battery system very tightly. Unlike my ICE cars, it might complain when it finds the low voltage battery giving weird results to tests.

On the other hand... If it tolerates this, and is smart enough to only employ the DC-DC board when the low voltage battery drops lower, and there's enough room between the high and the low voltage levels... Then it would certainly help. But you'd have to basically be consuming that power you're adding on the low-voltage system all the time least the rather small low voltage battery fills up.

-Crissa

 

[Woodrick]

That's what the solar "generator" battery is for. I only use the term "solar generator" because it's so common in the industry to call battery storage systems "battery generators" or "solar generators" even though I don't think it's very accurate or descriptive. I trust you know the basics.

Essentially, you feed the solar energy into the battery generator. Since battery generators can charge while you are drawing 120V current from the inverter you simply charge the car while the sun is shining. This is mostly to prevent the steady and predictable vampire drain that will eventually leave your battery flat (but with good solar conditions, and a good setup, you will be able to steadily add a bit a range to the battery every day). You can also run things off it, lights, charge devices, even a cooler if you have a reasonable solar array. That's in addition to adding a bit of range each day.

I would love it if Tesla offered DC charging inputs! And I'm sure they will some day, but probably not for a couple of years or more. By my estimation, DC solar inputs and a built-in MPPT charge controller would increase the output of your solar array by around 20-25% by bypassing the battery generator.

As I believe that I indicated earlier, show me the 150kWh portable battery suitable for charging the Cybertruck.

 

[Darthamerica]

I'm not going to do your shopping for you! Just Google solar battery generator. Look for one that is bundled with solar panels. Stick with the best names. You can generally add panels up to the maximum charge current the unit can handle. That's the most important number in this application, not the number of kWh of battery storage. It should also be able to output 15-20 amps at 120V.

You want the solar input to be at least 1000W, the higher this number, the more solar panels it can run. The battery itself can be as small as possible, as long as the input is high enough. I think you might find what you need with a battery of about 1.5 - 2 kWh.

You just plug your Mobile connector into this and start charging, whenever the sun is shining on the panels.

I'm not asking you to shop for me, I just want to see if you have found something that I haven't. A lot of details are left out of spec sheets on Amazon and other websites. People buy these things and find out the hard way that what looks like a "solution" on paper, doesn't work well in practice. I've tried many different methods to keep a Tesla running off grid for extended periods of up to 30 days and it was a struggle. I may have recovered 10 miles of range in a day best case! And that was on a Model S with ~ half of the battery capacity. It'll be even harder with a Cybertruck because you're dealing with a bigger battery AND a less efficient vehicle.

The only things that have worked reliably are ICE generators and 110V outlets when I have found them and didn't need to use the car at all and in very mild climates. Elon Musk wasn't exaggerating when he said you'd get about 15 miles best case on solar if you find something that works. For those pick a part DIY'ers out there who want to try and reproduce what they saw on YouTube, go for it! Just make sure you have the right expectations is all I'm saying.

 

[Woodrick]

This is a fun game, I will play. I am aiming for a self contained, no "deployment" solution. It would just pivot up like a tonneau cover to use the bed.

• Canadian Solar TOPBiHiKu7 700w
• EG4 6000XP | 8000W PV Input | 6000W Output | 120/240V Split
• EG4-WallMount Indoor Battery | 48V 280Ah | 14.3kWh
• ~$5,000

The solar panel is about 94"x51". The battery could hold about ~30 miles of charge. With 700w it gathers around 3.5kw per day, or ~5 to 7 miles in ideal conditions.

Over a 5 day trip, this would allow you to only go about 10 miles further into the boondocks.
How many more places do you get between 150 and 160 miles away from the last charge point?
Oh, and you can't use the truck during the day. It needs to stay pointed at the sun.

 

[Crissa]

As I believe that I indicated earlier, show me the 150kWh portable battery suitable for charging the Cybertruck.

That's a nonsensical statement, Woodrick.

For a stepped (non-integrated system) you only need as much battery as the solar energy you'll absorb between dumping it into the truck.

Which is usually 5 [average hours of solar absorption, vary by implementation] times [days between draining battery into truck] times [size if watts of panels].

So a single basic Ecoflow set is 400 Watts which means you only need 2kWh of battery per day it sits around generating power. Which is why the basic set is a 3kWh battery matched with at least one 400 Watt panel. (Which I have, but I use for the house, not camping.)

Elon Musk wasn't exaggerating when he said you'd get about 15 miles best case on solar if...

...If you forget that you're losing 2% of range per day due to electronics and battery management already. So solar would keep that from happening, totally.

It's clear Elon doesn't camp and never has to worry about a vehicle sitting somewhere it's not plugged in by a servant.

-Crissa

 

[Woodrick]

Tesla used to let you dial your mobile charger draw below 12amps. Is that no longer true?

-Crissa

I believe it is still true and I believe that I mentioned it. But it is NOT dynamic is my point. If you roll it down to 8A, then that's all you are going to get, 8A.
If you have full sunlight, it's not going to auto-adjust to 12A.

It's not the mobile charger that you adjust, it's the vehicle.

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